The invention relates to a single-use injector having a housing, in which or on which there are arranged—in each case at least in some areas—at least one mechanical spring energy store, at least one cylinder-piston unit—that can be filled at least temporarily with active substance—, at least one piston-actuating ram and at least one triggering unit, wherein the piston-actuating ram is positioned between the spring energy store and the piston of the piston-cylinder unit, wherein the spring energy store comprises at least one pretensioned spring element, wherein the piston of the cylinder-piston unit can be separately moved by means of a pump rod—when the spring element is pretensioned—, wherein the pump rod can be releasably coupled to the piston or to a piston rod of the piston, wherein the spring-loaded piston-actuating ram is supported by way of housing-side supporting portions and wherein the contact zone situated between the individual supporting portions and the piston-actuating ram represents part of an outwardly forcing wedge gear pairing.
DE 10 2007 031 630 A1 discloses, inter alia, an injector of this type. However, the injector does not have a piston that can be moved by being manually actuated. With the exception of the mechanical spring of the spring energy store, almost all the components of the injector are produced expensively from plastics by injection molding. Components that are subject to high mechanical loads are additionally reinforced with glass fibers.
FR 1 172 205 discloses a spring force-operated multi-use needle injector with an extendable injection needle. In the injector housing of the injector which has no pump rods, the chargeable spring storage structure is held between spring-resilient metal hooks.
US 2001/0051789 A1 discloses a needleless injector whose cylinder-piston unit can be filled via a piston rod integrated into the injector. The spring force-operated injector has a cylindrical plastic housing which consists for example of ABS and which has a release member which is manufactured from a stainless steel strap.
Therefore, the problem addressed by the present invention is that of developing a single-use injector of modular design which, with a small overall size, comprises only a small number of components and, while being easy to handle and inexpensive to produce, ensures safe storage and operation. It is also intended that the cylinder-piston unit of the tensioned single-use injector should be capable of being filled in the fitted state.